7th Grade Math PD

Caroline StalveyCharlotte Jenkins

Discovering PiCircles, Circles, Circles:• Have students

measure circles around the classroom or school. They should keep track of all data.

Credit: Bob Horton

Other options:• Canned foods

(cylinders) and string

• Walking the diameter of a circle on a playground.

Parallelograms and Triangles: Area

Before doing this activity students should be prepped on the areas so that they can fully

understand the concepts.

Trapezoids, Rhombi & Kites: Area

These activities can be done in a station setting and will allow

students to understand

where the area equations come

from.

Area Equations

Transitioning From 2-D to 3-DCylinder and Rectangular Prism

• Solids Formed ActivityNeed:– Deck of Cards– Roll of Pennies

• Have students recall the equations for the area of a circle and a rectangle.

• Demonstration• Extension: Oblique Solids

Rectangular Prism: Surface Area

Teaching Suggestion:Have students wrap a tissue box or other enclosed square item.

Cylinder: Surface Area

Teaching Suggestions: Have students wrap a canned food item.

Pyramids and Cones: Volume

• http://www.youtube.com/watch?v=OUDjY6vJ8pw

• http://www.youtube.com/watch?v=QnVr_x7c79w

Surface Area: Pyramid

Surface Area: Cone

Surface Area of a Sphere

Have students draw on prior knowledge by using the area of a circle and applying it to a sphere.

Relating the Volume of a Pyramid and a Sphere

• The volume of a sphere is the volume of a cylinder.

• Take clay and make it into a sphere. Cut out a cylinder with construction paper and put it around the sphere. Smash the clay down to prove that the volume of the sphere is 2/3rds that of the cylinder.

• The height on the cylinder would correspond with the diameter of the sphere or 2 times the radius of the sphere.

• So take the volume of a cylinder (v=pi*r^2*h) and substitute 2r in for the height.

• Take this multiplied by 2/3. When you simplify this you get V=Π.

http://bgssmaths.blogspot.com/2009/08/volume-of-cone-video.html

Supplementary and Complementary Angles

• Complementary angles – two angles whose measures add to 90 degrees

• Supplementary angles – two angles who measures add to 180 degrees

Ways to remember:

1.CO --> 90 SU --> 1802. Complementary --> "corner“ Supplementary --> "straight line"3. Alphabetical and Numerical Order

• Complementary comes before supplementary• 90 comes before 180